. >> reporter: he used a long steel rod to show us how loose rock left after blasting can easily be dislodged. that's why it has to be removed so it doesn't fall without warning and cause injuries. he says some of the big mines don't do this kind of maintenance and don't follow the existing safety rules. but after the cave-in, the owners insisted the miners survived because the company had followed the rules. but the company never finished building a mandatory escape ladder. if they had the miners had a clear path to it and could have used it to escape. that out rages nellie, whose son is is trapped in the mine. >> this mine should be closed. this is an unsafe mine. it doesn't haved ladders to get out. this is a mine that shouldn't continue giving work to anybody. it's been overworked. it's a mine overexploited. you can't continue to send people who go below this hill because it's dangerous. it's very dangerous. you shouldn't send anybody down there. miner or anybody. if it's not safe. >> reporter: mining company officials did not respond to requests for an on-camera interview. jessica cortez